You can read up on WUBI here.
But the basic answer to your question is - once you boot into Linux you are IN Linux and you will still need to install the drivers. You can see into the Windows file system just as you can on a dual boot system.
Hope that helps, I've never actually used Ubuntu running under WUBI but have used it to install on a couple of Windows boxes for friends. It is a very smooth install and the uninstall is remarkably simple.
Have fun with Linux!